Rainwater Harvesting

Installing a Rainwater Harvesting System at Home or Your Business Premises

 

Installing a rainwater harvesting system in your home can have a significantly positive impact on both your household bills and the environment around you. Rainwater is a resource that is under-utilised and often we forget that it can be reused for everyday tasks.

 

Why use rainwater harvesting?
Increasingly, building regulations are advising commercial and domestic dwellings incorporate rainwater harvesting into their design. By capturing rainwater, not only can homeowners and business owners then reuse this water reducing their bills, but they can also reduce the impact of building development on the local ecosystem. Construction can impact the natural run off water in an area and rainwater harvesting can be used as a mitigating factor in ensuring that any new development does not impact the immediate ecosystem.

 

Who wants rainwater harvesting?
We were recently asked to supply two rainwater harvesting systems to a customer in the mid-Norfolk area. The customer wanted to use the systems to irrigate garden areas, but also to wash cars and recycle water for use flushing toilets and clothes washing in a newly built dwelling. After a detailed consultation and a site visit, it was decided that a 6000 litre rainwater harvesting system would suffice for the new dwelling, with an additional 3800 litre rainwater harvesting system being fed from a large garage on the other side of the plot.

 

How do you size a rainwater harvesting system?
What size rainwater harvesting system you need will depend on a number of factors. Firstly, your location and the rainfall in that location is a key factor. Secondly, the surface area of the roof which you intend to use to capture the rainwater and finally, the intended usage. If you pick a storage tank that is too small, you will exhaust your supply too quickly and equally, it may fill too quickly meaning you waste a portion of the rainwater from your roof.

 

Equally, pick a storage tank too large and you will struggle to fill it enough for it to be cost effective. If in doubt, please get in touch and we will be happy to help you size the correct piece of equipment.

 

How do you install a rainwater harvesting system?
Installation of a rainwater harvesting system is relatively straightforward, especially if it is being used for garden irrigation and washdowns. There are more plumbing complexities when water is being recycled and used in the house or business premise for toilet flushing and clothes washing.

Installing the system requires a hole to be dug, a concrete base to be laid and enough room for the tank to fit and be back filled in. The 6000 litre Klargester rainwater harvesting system that was supplied for out mid-Norfolk customer was fed from two capture points on the roof of the new dwelling.

These were then piped using standard 110mm pipe directly to the rainwater harvesting tank. Rainwater harvesting tanks also often have the capacity to have a freshwater feed that ensures that the system never runs dry.

 

How do rainwater harvesting systems actually work?
Internally, a rainwater harvesting system is built incorporating filtration of incoming water which is then stored ready to be pumped either by a submersible pump or an external pump. The Klargester systems we provided were fitted with Grundfoss pumps, capable of extracting and distributing water at 3bar pressure – plenty of power to get the recycled rainwater to where it was needing to be used. The diagram below shows a typical rainwater harvesting system cutaway, detailing the intricacies of the system.

 

 

 

 

It is said that households can save up to 50% on their water bills when utilising rainwater harvesting. When you offset this saving and the positive impact on the environment, the investment could quickly pay off.

For more information on how we can help with rainwater harvesting applications for homes and businesses, please get in touch

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